Photographic development

ABSTRACT

A PHOTOGRAPHIC DEVELOPING METHOD PROVIDING INCREASED IMAGE DENSITY AND SENSITIVITY COMPRISING DEVELOPING AN EXPOSED LIGHT-SENSITIVE SILVER HALIDE PHOTOGRAPHIC EMULSION WITH AN ALKALINE SOLUTION CONTAINING A COMBINATION OF HYDROQUINONE IN A COMPOUND OF THE FORMULA   1-(R1-N(-R2)-),3-Y,4-(HO-),5-X-BENZENE   WHEREIN R1, R2, X AND Y ARE EACH ALKYL RADICALS HAVING UP TO 4 CARBON ATOMS.

Jan. 1, 1974 DENSITY DENSITY ATSLJAKI ARAI ETAL 3,782,946

PHOTOGRAPHIC DEVELOPMENT Original Filed 'Aug. 21, 1969 D 2 FIG. I |.5- L

I, I I #1 |.O-

l O 1 I T 3O 60 I20 240 (sec) TIME OF DEVELOPMENT D FIG. 2 E F -G l.5- H

TIME OF DEVELOPMENT INVENTOR;

United States Patent 3,782,946 PHOTOGRAPHIC DEVELOPMENT Atsuaki Arai, Kinji Ohkubo, Tatsuya Tajima, Mitsugu Tanaka, and Yosinori Tutiya, Kanagawa, Japan, assignors to Fuji Photo Film Co., Ltd., Minami Ashigarashi, Kanagawa, Japan Continuation'of abandoned application Ser. No. 851,854, Aug. 21, 1969. This application Mar. 9, 1972, Ser. No. 233,309

Claims priority, application Japan, Aug. 21, 1968, 43/59,672 Int. Cl. G03c 1/06, 5/26, 5/30 U.S. Cl. 96-663 12 Claims ABSTRACT OF THE DISCLOSURE A photographic developing method providing increased image density and sensitivity comprising developing an exposed light-sensitive silver halide photographic emulsion with an alkaline solution containing a combination of hydroquinone in a compound of the formula wherein R R X and Y are each alkyl radicals having up to 4 carbon atoms.

REFERENCE TO CROSS-RELATED APPLICATION This application is a continuation application of United States patent application Ser. No. 851,854, filed Aug. 21, 1969, now abandoned and claiming priority from Aug. 21, 1968, based on Japanese patent application Ser. No. 59,672/ 68.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to photographic development.

(2) Description of the prior art It is known that a photograph is obtained by exposing imagewise to light a photographic light-sensitive material which comprises a support such as glass, paper and/or a plastic film and at least one photographic silver halide emulsion layer, developing it in an alkaline developer solution containing a developing agent, stopping, fixing, washing and drying. Such processing requires a long time. Many methods of processing that require less time have accordingly been proposed. Among them, high-temperature processing, monobath processing, and two-bath stabilization processing have been proposed.

The last is a recently-developed process of obtaining a photograph by subjecting an exposed silver halide emulsion layer containing a developing agent to an activator solution containing alkali, antioxidant, fog inhibitor, etc., and then to a stabilizing solution which forms a colorless complex with silver halide.

The silver halide complexes formed in such a process are colorless and reasonably stable to light, heat, humidity and atmospheric contaminants.

When photographic materials, which may comprise a silver chlorobromide emulsion, contain a high silver bromide content, a silver bromide emulsion, or a silver iodobromide emulsion containing developing agents, are subjected to an alkaline activator solution, the development speed of such silver halide emulsions is so slow that they are insufliciently developed in the development time period of conventional two-bath stabilization processing. Therefore, high density and gradation of prints cannot be obtained.

3,782,946 Patented Jan. 1, 1974 On the other hand, it has been well known that, in conventional processing of an exposed light-sensitive photographic silver halide element which does not contain a developing agent in the light-sensitive element, satisfactory photographic characteristics can be obtained by using developers which contain hydroquinone and an auxiliary developing agent, such as 1-phenyl-3-pyrazolidone and N- methyl-p-aminophenol.

These auxiliary developing agents show super-additivity when they are used in combination with hydroquinone.

In the specification of U.S. Pat. No. 2,751,297, it is disclosed that development by a conventional Metol-hydroquinone (Metol is a trade name of N-methyl-p-aminophenol sulfate) developer is accelerated by adding 3- pyrazolidone derivatives to a silver halide emulsion. We therefore attempted to accelerate development in two-bath stabilization processing of silver chlorobromide emulsion having a high silver bromide content, a silver bromide emulsion, or a silver iodobromide emulsion by adding 1- phenyl 3-pyrazolidone or N-methyl-p-aminophenol to these emulsions, which contain hydroquinone.

However, when 1-phenyl-3-pyrazo1idone or N-methylp-aminophenol is added to a silver halide emulsion containing hydroquinone, they are easily oxidized by atmospheric air and the photographic elements containing them have such shortcomings that the super-additive efiect development is decreased by aerial oxidation of that developing agent and the background of the photographic print is discolored.

Likewise, some p-aminophenol. derivatives accelerate development speed of an emulsion layer that contains hydroquinone when they are added to the emulsion layer.

As examples there are 4-(N,N-diethylamino)-2-rnethyl phenol hydrochloride, described U.S. Pat. 3,134,673 and l-(3,5-dimethyl-4-hydroxyphenyl)-PYrolidine hydrochloride, described in U.S. Pat. No. 3,265,499.

When they are added to a light-sensitive silver halide emulsion layer with hydroquinone to accelerate the development of two-bath stabilization process, however, the photographic element is easily fogged. Moreover, when antifoggant is added to the emulsion to inhibit this fog, the development is extremely retarded.

SUMMARY OF THE INVENTION On the other hand, when we added a combination of a compound represented by Formula 1 and hydroquinone to a light-sensitive silver halide emulsion layer and carried out development according to the two-bath stabilization process, we found that the above-mentioned shortcomings were eliminated and the photographic element had been developed with considerable increase in density. Moreover, we also found that an alkaline developer containing a combination of the compound represented by Formula 1 and hydroquinone is. an excellent photographic developer.

The compounds of the present invention are selected from those having the formula:

wherein R and R represent the same or diiferent alkyl radicals having 1 to 4 carbon atoms and X and Y represent the same or different alkyl radicals having 1 to 4 carbon atoms.

These novel compounds are generally used in the form of their acid salts such as hydrchloride, sulfate, or naphthalene disulfonate', which are more stable than the free amino form.

An object of the present invention is to improve the development of the two-bath stabilization process which is carried out by adding the compound represented by Formula 1 and hydroquinone to a light-sensitive silver halide emulsion layer or its adjacent layer.

Another object of the present invention is to provide an improved developer composition containing hydroquinone and the compound represented by Formula 1.

Still another object of the present invention is to increase conventional development speed by adding a compound represented by Formula 1 to a light-sensitive silver halide emulsion layer.

DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, the compound represented by Formula 1 can either be added to a photographic silver halide emulsion layer and/or to another layer of a photographic material, for example, a layer which is adjacent to a silver halide emulsion layer.

The compound is preferably employed in an amount in the range of 0.5 to 50 grams per mol of light-sensitive silver halide present. When the compound is added to a developing solution, it is added at a concentration in the range of 0.05 to grams per liter of alkaline developer.

Photographic materials comprising pure silver chloride emulsion, silver chlorobromide emulsion, silver bromide emulsion, silver iodobromide emulsion, any of which contain the compound of the present invention, possess high ima-ge density when developed. The compounds of the present invention are particularly effective for such photographic materials as those comprising silver ch1orobromide emulsion, silver bromide emulsion, silver iodobromide emulsion, which are relatively slow in development when these, that contain hydroquinone, are developed by surface application of an alkaline solution.

The support for the photographic material used in the present invention may comprise paper, plastic film, paper coated with a synthetic resin such as polyethylene or with baryta, and the like.

The binder of the light-sensitive silver halide emulsion can comprise gelatin or a synthetic resin such as polyvinyl alcohol, polyvinyl acetal, and the like.

The preparation of compounds represented by Formula 1 which are used in the present invention will be illustrated by the following:

Preparation of Compound 1 [4-(N,N-diethylamino)- 2,6-xylenol hydrochloride] 15.3 g. of 4-amino 2,6 xylenol, 35.2 g. of methyl iodide and 15.4 g. of anhydrous potassium carbonate are heated under reflux in 180 cc. of absolute alcohol for 12 hours. The reaction mixture is filtered while hot, the solid residu is extracted twice with hot alcohol and the extracts are combined and filtered.

The filtrate is dreid by evaporation under reduced pressure and the residue is extracted with hot ether. Concentration of the extract gives an oily residue which is distilled under reduced pressure to yield 4-(N,N-diethylamino)-2,6-xylenol boiling at 111-1 14 C./1 mm. Hg.

The 4-(N,N-diethylamino) 2,6 xylenol obtained is obtained is dissolved in 200 cc. of ether and dry hydrogen chloride is passed through the solution to precipitate a white powder, which is recrystallized from a mixture of ethanol and benzene to give the 4-(N,N-diethylamino)-2,6-xylenol hydrochloride in the form of colorless leaflets melting at 207-209 C.

Preparation of Compound 2 [4-(N,N-dimethylamino)- 2,6-xylenol hydrochloride] A mixture of 13.7 g. of 4-amino 2,6 xylenol, 28.4 g. of methyl iodide, 13.8 g. of anhydrous potassium carbonate and 200 cc. of absolute ethanol is heated under reflux with stirring for 7 hours. The reaction mixture is filtered and the solids are washed twice with ethanol. The filtrate and washings are combined. After the ethanol is evaporated, the residue is extracted twice with ether. The ether extracts are evaporated, and the residue is distilled under reduced pressure.

The fraction boiling at 104-108 C./1 mm. Hg is collected and dissolved in ether and dried hydrogen chloride is then passed through the solution to produce a white powder. Recrystallization from 3% aqueous hydrochloric acid gives sublimable, colorless crystals melting at 268-273 C. (decomposed).

Preparation of Compound 3 [4-(N,N-di-n-butylamino)- 2,6-xylenol hydrochloride] A mixture of 16 'g. of 4-amino 2,6 xylenol, 43 g. of n-butyl iodide, 16 g. of anhydrous potassium carbonate and 300 cc. of absolute ethanol is refluxed with stirring for 13 hours. The reaction mixture, after being treated in the same manner as in the preparation of Compound 2, is distilled under reduced pressure to obtain 4-(N,N-di-nbutylamino) 2,6 xylenol boiling at 138-141 C./1 mm. Hg. The 4 (N,N-di-n-butylamino) 2,6 xylenol thus obtained is dissolved in ether and dried hydrogen chloride is passed through the solution to precipitate a white powder. Recrystallization from an alcoholic hydrochloric acid solution gives sublimable, colorless crystals melting at 233.5-235.0 C.

Preparation of Compound 4 [4-(N,N-diethylamino)- 2,6-di-t-butyl-phenol hydrochloride] 18 g. of 2,6-di-t-butyl 4 amino-phenol, 25.4 g. of ethyl iodide, 11.2 g. of anhydrous potassium carbonate and 200 cc. of absolute ethanol are refluxed with stirring for 9 hours. The reaction mixture, after being treated in the same manner as in the preparation of Compound 2, is distilled under reduced pressure to collect 4-(N,N-diethylamino) 2,6 di-t-butyl-phenol boiling at 113-115 C./1 mm. Hg, which is then dissolved in ether. Dry hydrogen chloride is then passed through the solution to precipitate a white powder. Recrystallization from an alcoholic hydrochloric acid solution gives 4-(N,Ndiethylamino) 2,6 di-t-butyl-phenol hydrochloride as sublimable, colorless prisms melting at 230234 C. (decomposed).

The present invention will be further illustrated by the following examples:

EXAMPLE 1 An emulsion was prepared by adding 10 g. of hydroquinone, 1.5 cc. of a 30 wt. percent aqueous solution of formalin as a hardening agent and 3 cc. of saponin as a wetting agent, to 400 g. of gelatino silver halide emulsion containing 50 g. of gelatin and 20 g. of silver chlorobromide (silver bromide, 60 mol percent). To separate portions of this emulsion were added the compounds of the present invention shown in Table 1 and well-known developing agents for the purpose of comparison.

These separate portions were coated on a glossy baryta paper. The coatings were exposed in an intensity-scale sensitometer through a step wedge and processed in a conventional stabilization processor with approximately 4 seconds activation at 20 C. and with surface application of the following activator:

G. Sodium sulfite (anhydrous) 45 Sodium hydroxide 48 Potassium bromide 1.3

Water to make 1,000 cc.

6 EXAMPLE 4 An emulsion was prepared by adding a suitable amount of hardener and coating aids to 4. g. of gelatino silver halide emulsion containing 50 g. of gelatin and 2 0 g. silver iodobromide (silver iodide 1.5 mol percent). To separate portions of this emulsion were added 0 and 0.5 g. of 4-(N,N-diethylamino)-2,6-xylenol hydrochloride (Compound 1). These separate portions were coated on glossy baryta paper. The gelatin solution comprising 20 g.

TAB LE 1 Routine coatings incubated coatings Specific Maxi- Specific Maxi- Developmg agents added to each 400 g. of the sensimum sensimum t g 911111181011 tivity density Gamma Fog tivity density Gamma Fog A fiydroquinvne. 10 s- (control) 1.00 1.00 1.4.4 0.01 1.00 0.75 0, 07 0,01 B gg 10 a P1115 -p e y -pyra o11done, 1.62 1.34 1. 37 0.02 3,70 0,94 1 2 g. C fiy g ggg 10 ap y p-ami ophenol 1. 52 1. 28 1. as 0.02 a. s4 0. 91 1, 26 0. 02

s a e, g. D Hydroquinone, 10 g. plus 4-N,N-diethylamino)phenno1hydrochloride,0.40 g. 1.53 1. 30 1.88 0.02 3.80 0. 92 1. 32 0.02 E Hydroq o 10 p 4-( ethy1am1no)-2- 1. 70 1.48 2.01 0.02 0,80 1.09 1,52 002 methylphenol hydrochlonde, 0.42 g. F Hydroquinone, 10 g. plus l-(3,5dimethyl-4-hydro- 1. 54 1.38 1.87 0.25 4. 76 0.88 1.10 0.23

xyphenyDpyrolidine hydrochloride, 0.45 g. G Hydroquinone, 10 ap s .N-diethy1amm0) -2,fi- 2. 04 1. 72 2. 41 0. 03 s. 95 1. 2s 1. 91 04 xylenol hydrochloride, 0.45 g. H Hydroqui one, 10 1;. pl s ,6-d -t-buty1-4-(N.N-d1- 2.00 1.68 2. 32 0. 04 s. 21 1.22 1.83, ,0

ethylamino)phenol hydrochloride, 0.60 g. 1 Hydroquinone, 10 plus 4-(N,N-di-n-buty1am1 o)- 1. 98 1.71 2. 43 0. 02 s. 43 1, 26 1,90 02 2,6-xy1enol hydrochloride, 0.60 g. I J Hydroquinone, g. plus 4-(N,N-d-\m thv1a 0)- 1.9 1.68 2. 37 0. 02 8.40 1.25 1. 7 0, 02

2,6-xylenol hydrochloride, 0.40 g.

EXAMPLE 2 An aqueous gelatin solution, comprising g. of gelatin, g. of hydroquinone, benzene sulfinicacid as an antloxidant for the developing agent, 3 cc. of an aqueous 30 wt. percent formaldehyde solution and 1 liter of water was prepared.

To separate portions of this gelatin solution were added 0 and 1.2 g. of 4-(N,N-diethylamino)-2,6-xylenol hydrochloride (Compound 1) of the present invention.

These separate portions were coated on a glossy baryta paper over a gelatino silver halide emulsion layer containing 50 g. of gelatin and 20 g. of silver chlorobromide (silver bromide 60 mol percent) per 400 g. of the emulsion. The coatings thus prepared were treated in the same manner as in Example 1.

The coating containing Compound 1 was higher in sensitivity, maximum density and gamma than the others.

When these coatings were incubated at 50 C. and 90% RH for one day, the coating containing Compound 1 was higher in sensitivity, maximum density and gamma than the others.

EXAMPLE 3 A gelatin solution comprising 50 g. of gelatin, g. of hydroquinone, 2 g. of benzene, sulfinic acid as an antioxidant for the developing agent, 1.0 g. of a fluorescent whitening agent (trade name: Blankophor BUP', mannfactured by Bayer Co., West Germany), a suitable amount of hardener and 1 liter of water was prepared. To separate portions of this gelatin solution were added 0 and 1.2 g. of 4-(N,N-diethylamino)-2,6-xylenol hydrochloride (Compound 1) of the present invention.

These separate portions were coated on a glossy baryta paper. A gelatino silver halide emulsion containing 50 g. of gelatin, silver chlorobromide (silver bromide 60 mol percent) per 400 g. of this emulsion was then coated thereon.

The coatings so prepared were treated in the same manner as in Example 1.

The coating containing Compound 1 was higher in sensitivity, maximum density and gamma than the others.

When the coatings were incubated at 50 C. and 90% RH for one day, the coating containing Compound 1 was higher in sensitivity, maximum density and gamma than the others.

of gelatin, a suitable amount of hardener, coating aids and 1 liter of water was then coated thereon.

The coatings thus prepared were exposed in an intensity-scale sensitometer through a step wedge and were developed by using Kodak D-72 developer. Density against development time at constant exposure level was shown in FIG. 1.

In FIG. 1, the abscissa and the ordinate show development time in seconds, and density, respectively. Curve 2 and 2 show the results with coatings which contain Compound 1. On the other hand, curves 1 and 1 show the control. Solid lines show the results obtained with routine coatings. Dotted lines show the results obtained with incubated coatings. From the curves shown in FIG. 1, it will be seen that the photographic element containing Compound 1 is higher in density after shorter development time than the others.

EXAMPLE 5 Anhydrous sodium sulfite --g 20 Hydroquinone g 3 Anhydrous sodium carbonate 15 Potassium bromide 1 Developing agents as shown below mo 0.00137 Water to make 1,000 cc.

Curve None A l-phenyl-3-pyrazolidone B N-methyl-p-aminophenol sulfate C 4-(MN-diethylamino)-2-methylphenol hydrochloride D 4-(N,N-diethylamino)-2,6-xylenol hydrochloride E 4 -.(N,N diethylamino) 2,6 di t butyl phenol hydrochloride 1 Curve 4-(N,N-di-n-butylamino)-2,6-xylenol hydrochloride G 4-(N,N-dimethylamino)-2,6-xylenol hydrochloride H Density against development time at constant exposure level was measured. The results are shown by the curves in FIG. 2. Curves E to H which are obtained with coatings which contain a compound of the present invention are shown to have an extermely high development speed.

EXAMPLE 6 An emulsion was prepared by adding 10 g. of hydroquinone, a suitable amount of hardener and coating aids to 1 kg. of a gelatino silver halide emulsion containing 125 g. of gelatin and 40 g. of silver chlorobromide (silver bromide 60 mol percent). This emulsion was coated on a glossy baryta paper. The coatings were then exposed and processed according to Example 1 with surface application of either an activator which contains 0.6 g. of 4-(N,N-diethylamino-2,6-xylenol hydrochloride (Compound 1) or an activator which does not contain the compound. The activation was followed by stabilization according to Example 1. The sensitometric values obtained are shown in Table 2.

TABLE 2 Maximum density Relative sensitivity Gamma Activator not containing Compoundl.-- Activator containing Compound 1 It can readily be seen that the sample coating processed with the activator containing Compound 1 is higher in sensitivity, maximum density and gamma than the others.

EXAMPLE 7 Anhydrous sodium sulfite Hydroquinone Sodium hydroxide Potassium bromide Water to make 1,000 cc.

The activation was followed by stabilization according to Example 1. The sensitometric values obtained are shown in Table 3 below. From the results, it can be seen that the coating containing Compound 1 is higher in sensitivity, maximum density and gamma than the others.

TABLE 3 Maxi- Relative mum sensitivity density Gamma.

Coating not containing Compound 1..-- Coating containing Compound 1 What we claim is:

1. A photographic developing method which comprises developing an exposed, light-sensitive silver halide emulsion layer of a photographic material with an alkaline solution in the presence of a combination of hydroquinone and a derivative of p-aminophenol having the formula wherein R R X and Y are each alkyl radicals having up to 4 carbon atoms, said hydroquinone and said derivative capable of being employed alone or in combination in any one of said silver halide emulsion layer, said alkaline solution, or a layer of a photographic material placed adjacent to said silver halide emulsion layer.

2. The method of claim 1, wherein said photographic material further comprises a layer of a photographic material adjacent to said silver halide emulsion layer, said hydroquinone being incorporated in said alkaline solution, layer and its adjacent layer, and said derivative being incorporated in said alkaline solution.

3. The method of claim 1, wherein said photographic material further comprises a layer of a photographic material adjacent to said silver halide emulsion layer, said hydroquinoneb eing incorporated in said alkaline solution, and said derivative being incorporated in at least one of said layer and its adjacent layer.

4. The method of claim 1, wherein said photographic material further comprises a layer of a photographic material adjacent to said silver halide emulsion layer, said hydroquinone and said derivative being both incorporated in at least one of said layer and its adjacent layer.

5. The method of claim 1, wherein said photographic material further comprises a layer of a photographic material adjacent to said silver halide emulsion layer, said hydroquinone and said derivative both being incorporated in said alkaline solution.

6. The method of claim 1, wherein said derivative is present in an amount of from 0.5 to 50 g./mol of lightsensitive silver halide.

7. The method of claim 2, wherein said derivative is incorporated in an amount of from 0.05 to 10.0 g./liter of said alkaline solution.

8. The method of claim 5, wherein said derivative is incorporated in an amount of from 0.05 to 10.0 g./liter of said alkaline solution.

9. The method of claim 1, wherein said derivative is a member selected form the group consisting of 4-(N,N-diethylamino)-2,6-xylenol hydrochloride, 4-(N,N-dimethylamino) 2,6-xylenol hydrochloride, 4 (N,N dipropylamino) 2,6 xylenol hydrochloride, 4 (N,N dibutylamino) 2,6 xylenol hydrochloride, 4-(N,N-dimethylamino)-2,6-diethylphenol sulfate, 4-(N,N-diethylamino)- 2,6-diethylphenol hydrochloride, 4 (N,N dimethylamino)-2,6-dipropylphenol naphthalene-1,5-disulfonate, 4- (N,N-diethylamino)-2,6-dipropylphenol hydrochloride, 4- (N,N-dimethylamino)-2,6 dibutylphenol hydrochloride, and 4-(N,N-diethylamino)-2,6-dibutylphenol naphthalene- 1,5-disulfonate.

10. A photographic material having at least one lightsensitive silver halide emulsion layer, and which may contain an additional layer adjacent to said silver halide emulsion layer, either one of said layers containing a conbination of hydroquinone and a p-aminophenol derivative of the formula:

wherein R R X and Y are each alkyl radicals having up to 4 carbon atoms.

11. An alkaline photographic developing solution containing a combination of hydroquinone and a p-aminophenol derivative of the formula:

/N CH 2 wherein R R X and Y are each alkyl radicals having up to 4 carbon atoms.

12. A photographic developing method which comprises developing an exposed, light-sensitive silver halide emulsion layer of a photographic material which may further contain a layer adjacent to said silver halide emulsion layer, with an alkaline solution in the presence of a combination of hydroquinone and a derivative of p-aminophenol selected from the group consisting of 4-(N,N-diethylamino)-2,6-xyleno1 hydrochloride, 4-(N,N-dimethylamino)-2,6-xy1enol hydrochloride, 4-(N,N-diproylamino)-2,6-xylenol hydrochloride, 4-(N,N-dibutylamino)- 2,6xylenol hydrochloride, 4-(N,N-dimethylamino)-2,6-diethylphenol sulfate, 4-(N,N-diethylamino)-2,6-diethylphenol hydrochloride, 4-(N,N-dimethylamino)-2,6-dipropylphenol naphthalene-1,5-disulfonate, 4-(N,N-diethylamino)-2,6-dipropylphenol hydrochloride, 4 (N,N dimethylamino)-2,6-dibutylphenol hydrochloride, and 4- (N,N-diethylamino)-2,6-dibutylphenol naphthalene 1,5- disulfonate, said hydroquinone and said derivative capable of being employed, alone or in combination, in any one of said silver halide emulsion layer, said adjacent layer, and said alkaline solution, said derivative, when being References Cited UNITED STATES PATENTS 3,134,673 5/1964 Gauguin 9666 R 3,276,873 10/1966 Green 96-29 3,295,978 1/1967 Barr 96-66.4 3,600,176 8/1971 Haist et a1 96-66 J. TRAVIS BROWN, Primary Examiner M. F. KELLEY, Assistant Examiner US. Cl. X.R'. 96-66 R, 95, 50 R 

